Is it possible to change the RPM that the 3.4 idles at? I'm concerned with the "warm" idle and not the cold start idle. I'd like the RPM's to stay around 800-850 RPM when fully warm compared to 650 RPM. I was thinking you'd get a little better pickup off the line. I'd also like to do this because my truck has lost it's "hill hold" capability thanks to 285's, and a bit of a higher RPM would bring back that quote-unquote "feature". Is this possible, or just a silly idea?

 

Is there not an idle adjustment screw in there somewhere.

 

There is no idle adjustment on the 3.4, it's controlled by the ecu. Spec is 700 +/- 50 rpm.

 

There is no idle adjustment per se BUT there is a way to adjust your idle up on demand from the cab if you want to by using the Fog-Mod

What I did was install a switch to put a varbile resistor in line with the engine temp sensor. With the switch in one position it allows the ECU to see the real resistance of the temp sender. But with a flip of a switch it puts the variable resistor in-line with the temp sender and as you increase the variable resistor you raise up the idle.

I have mine set up as a high idle switch so when I flip in the variable resistor it bring the engine up to 1300 RPM so the A/C works ALLOT better in hot weather, the alternator will put out full power and the engine will keep around 25 psi of oil pressure.




FOG

 

I'm pretty interested in changing the idle speed as well. I live in Seattle and there are quite a few hills here. Every time I have to stop on one my 4runner rolls back a lot. I searched and couldn't find anything related to the" hill hold " feature and assume that increasing the idle speed will solve this problem.

 

You can adjust the idle if you have a piggyback on the ECU like me. Just mess with the global fuel trim setting.

OK, that's not realistic. Similar to what Fog mentioned above, you could do something with the A/C switch (but where it doesn't actually kick on the compressor) in that the idle would bump up as the ECU thinks the A/C is on. You might need an EE degree, but it is a thought.

Other than a throttle cable adjustment (which I don't think applies to a 02 due to throttle by wire) I think you're out of luck.

 

No idle adjustment? B.S. unless you guys have drive-by-wire? I adjusted mine from 700RPMs to around 825-850 RPMs. It was a PITA but underneath the throttle there is a 10mm nut and a hex screw in it. I found it easier to take the whole nut/screw out as an assembly, adjusting it and reinstalling it. I may be doing the ISR mod this weekend so I'll post some pics of where the adjustment can be made.

 

01 and 02 had drive by wire, to some extent. The throttle cable only opens the butterfly part way, and some type of small motor or servo opens it the rest of the way. However, I might try tightening up the throttle cable and see if that changes anything. If it doesn't, I can always put it back to how it was before. Thanks for the input

 

cheapest way is a brick for the gas pedal

 

As promised here is the pic on mine. I don't know how to do the arrows to point it out but if you look to the left of the throttle opening you can see the adjustment (in the yellow). I'm not sure if it's the "proper way" of doing so, but I adjusted the end with a 10mm wrench and an allen head wrench to bump up my idle.

 

I'm not clear on what part you're referring to.

When I was fiddling with my TB, I noticed there was a screw behind the throttle opener that seemed adjustable. What does that do?

Here's a photo of the screw I'm talking about in one of 99runner4me's photos (my arrow).






I was also wondering about those two short metal bits above the throttle valve (on mine, they're capped). What are they and what do they do?

 

That does not look like mine, did this come off your 4clyinder? But yes I was referring to the screw just above the arrow in the first picture. I had to loosen the jam nut and move the screw inwards to increase the idle and keep my voltage from the alternator from dropping too low at a stop. I was noticing the drop in voltage on my scan gauge2 with headlights on, A/C or heat on from 13 volts down to 11 volts. Granted I know with the accessories on they will drop some, but not that much. I went through 3 alternators before I decided to increase the idle. It fixed the problem.

As far as your second picture, I have no clue what those 2 tubes are for. Mine are also

 

Water bypass inlets?

 

No, that's actually another person's photo, but it looks like the one off our 6 cylinder.

 

Oh ok, just looks different with the TB separated, but yes that was the adjustment that I used on mine. You have to hold the screw with an allen wrench (can't remember what size though) but IIRC the jam nut was a 10mm. Just hold the screw in place and back off on the jam nut. I had to take the whole thing out to adjust it because it was easier that way. It took a few tries to get the idle where I wanted it because I couldn't remember which way increased/decreased the idle. Right now I've got it around 850 RPMs and it does just fine for what I wanted.

 

dont quote me on this but i believe thats for the cruise control

 

Right next to the carburetter.

I, on the other hand, instead of turning unknown screws, just put a screwdriver in the throttle. It keeps it from closing all the way. Idles nice and high now.

I have that too. Awesome mod! But when I forget to switch it off, I get 2MPG for some reason.